Electric switch



w. A. ATwOoD ELECTRIC SWITCH Filed April 21, 1924 Invent or":

Winfield A. Atwood,

by M His Attorney. I

Patented May 1-0, 1927.

pairs". STATES Para-Mr GFTHQE.

WINFIELD A. ATWOOD, or SGHENECTADY, NEW YORK, ASSIGNOR ro GENERAL ELEC- TRIO COMPANY, A CORPORATION or new YORK.

ELECTRIC SWITCH.

Apphcation filed April 21, 1924. Serial No. 707,832.

My invention relates to improvements in electric switches and more particularly to improvements in electric switches adapted to be used as auxiliaries in the control of sired operation, auxiliary devices operativev with a time lag are employed. These de vices may be actuated electrically as in the case of control relays or mechanically as in the case of auxiliary switches associated with the circuit breaker closing mechanism. In either case, it is necessary especially when large circuit breakers are to be operated, and particularly solenoid operated, to provide a relatively high current interrupting capacity.

An object of my invention is, therefore, to provide an improved electric switch which has a mechanically delayed action, especially in opening, and which is particularly adapted for direct mechanical connection to the closingmechanism of a circuit breaker so as to control the energizing of the closing mechanism, particularly with reference to a predetermined position of the circuit breaker mechanism. Another object of my invention is to provide a comparatively sim ple form of switch which is conveniently adjustable so as always to ensure positive operation at the desired instant and which has the requisite current interrupting capacity.

My invention will be better understood from the following description taken in connection with the accompanying drawing and its scope will be pointed out in the appended claims.

Figs. 1 and 2 show in elevation an embodiment of my invention in circuit closed and open positions respectively, Fig. 3 shows in elevation a modification of my mvention in circuit closed position, and Fig. 4

shows )artly in elevation and partly in diagram the embodiment of my invention shown in Figs. 1 and'2 as applied to a solenoid operated circuit breaker. I

The embodiment of-my invention illustrated in Figs. 1, 2 and 4 comprises relatively mo able cooperating contacts 1 and 2 which are mounted on a frame or body 3' adapted for mounting on a switchboard 4.

or the like. The fixed contact 1 is suitably insulated from the frame 3 and themovable contact 2 1s mounted on an arm 5 carried on a pivot 6 in the frame 3. The movable contact 2 may be. provided with a secondary or carbon contact 7, especially when relatively large currents have to be interrupted asis often the case with solenoid-op- I erated high capacity circuit breakers. V For moving the contact 2 to and from circurt closing position, I provide an actuatingmeinbersuch as a crank 8 which is carried on a pivot 9 in the frame Sand which is connected to the arm 5 by a pivot 10;

The crank S is arranged so that upon movement in one direction, clockwise with referf ence to Figs. 1, 2' and 4, the contact 2 is moved to circuit closing position and upon movement in the opposite direction, counter clockwise with reference to Figs. 1, 2 and 4,. the contact 2 is moved to circuit opening position. Since the arm 5 and crank 8 are arranged for movement on pivots 6 and 9 respectively and these, pivots are fixed relatively to the pivot 10, the hole 10 in the crank 8 through which the pivot 10 passes is made, larger than the diameter of the pivot 10 in order to permit movement of the pivot 10 in a path across the line through pivots Gand 9. The circuit opening movement is preferably very quick, especially at r the beginning, so as to provide snap action at the contacts. This movement 1s obtained by a biasing spring 11 connected between the pivot 6 and a pin 12 near the end of one.

arm of the crank 8 so as to have energy stored in it during the contact closing motion of the crank 8 and to tend to turn the crank in the contact opening direction.

For actuating the crank 8 in contact cl'osing direction, I provide suitablemeans such as an operating member 13 carried" on a pivot 14 in the frame 3. ed on the operating member 13 is arranged to engage a curved portion 16 on the crank 8 upon movement of the operatingniember A roller 15 mountiii! 13 in one direction. counter-cloekwisc with reference to Figs. 1 and 2. In order to rcstrain the crank 8 from movement to contactopening position under the bias of spring 11, until a. predetermined mm'ement oi? the operating member 13, 1 provide a restraining;- member 17 carried on the pivot i l and arranged to slide over a curved or arcuate portion 18 of the crank 8, the center oicnrvature of which is, in the contact closing. position ot' the crank, in the axis of the pivot 1 1. For moving the restraining member 1? from restraining position, it is arranged to abut the operating member 13 so that upon a predetermined clockwise movement of the operating member, the restraining member 1? is moved clear of the ancnate portion 18 of the crank 8 as shown in Fig. 2. hen the restraining member ii" is thus moved from restraining position, the crank S is free to move to contact opening position under the bias of the spring 11, and the parts are positioned substantially as shown in Fig. 2. The contact opening movement of the crank 8 may be limited in any suitable manner such as having the pivot 10 abut extensions on the side portions of the frame In order to return the restraining member 17 t restraining position when the switch is closed, I provide suitable biasing means such as a spring 19 arranged to have energy stored therein upon countcr-clockwisc movemeat of the operating member 131. 'lhis spring may be of the torsii'in type having its ends secured to the restrainingand operat ing members respectively. The operating member 13 is thus arranged to effect move meat 01': the restraining; member 17 to restraining position. i

In Fig. i, I have illusli 'aied my invention as applied to the control circuit 01? a sole noid 20 arranged when energised to close a. circuit breaker 21. The control circuit of the solenoid 20 is connected across a supplvbus and includes in series with the solenoid coil, a normally open control switch 33 and the contacts 1 and 2- ol? an anxiliarv switch such as shown in Figs. land .lhe

operating member 13 oi the ausiliiir r switch is connected directly to the rock shaft 'L-l; oi the circuit breaker closing: mechanism Qei. by a iink and a crank 26 so that the con" tacts 1 and are closed when the circuit breaker 21 is open, and are opened when the circuit breaker is closed suilicienllv to be latched positively. in this wav. it is impossible for an operator to hold the circuit breaker 521 closed on a faulty line by keeping the switch 28 closed.

The link .25 is shown more in detail in Figs. 1 and and may coniprise two thread ed portions 27 and 28 oi? dillercnlt pitch so as to provide a micrometer adjustment tor the position oi the operating member 13 with respect to the latchcd-in position of the circuit breaker 21 in order to imuu'e that the restraining member 17 will be moved clear of the crank 8 at the right instant.

in the embodiment of my invention shown in Fig. 3, the lined and movable contacts 1 and 2 are supported by a frame 3. the movable iontact being mounted on an arm 29 carried on a pivot Eli). The restraining member 1'? and the opcraiimr member 13" are carried by a pivot 31 in the frame 3 and the restraining member is provided with an arcuate or curved flange 32 against which a projecting portion 33 of the arm 29 is arranged to abut so as to restrain the movable cootai'lt 2 from moving to circuit opening position until a n'edeterminedmovement of the operating member 13'. i

in order to close the switch, the arm 29 provided with a project-ion such a pin 34; arranged to abut and slideon a portion 35 of the operating member 13. Similarly, in order to more the restraining member 17 from restraining position, it provided with a projection such as a pin 36 arranged to abut the edge 3? of the operating member 3. For moving the restraining member ii to restraining position and the contact to circuit opening position, a biasing spring iltl connected between the pins 3 1 and 36, is provided. 1

Assuming the parts positioned as shown in il ig. 3, it will be clear that, when the operatinp; member .3 is moved chiickwisc, it will bear against the pin 36 and thereby move the restraining member clock-wise. But, as the portion 33 of the arm Elli-abuts the flange 32 oi the restraining member 17', the arm S39 cannot move until the flange 32 has been.

moved clear oi? the projecting portion 33. Conscmicntly, energ stored in. the spring 38 so that upon a.predetermined clockwise moven'uent of the oiiierating member 13, the restraining member is moved suiliciently for the flange 32 to release the arm 29 which is then (prickly snapped to the circuit opening position. The circuit opening position of the arm E2!) is limited by the pin :34: coming to rest against the portion oi the operating menu ber 13. hen the operating member 1?) is moved colinter-rlockwisc. the pin 34 abuts the portion 35 of lhe oi'icrating member and moves ti i arm E39 lo contact closing position. During this circuit closing movement, how ever the projecting portion if) is not high enough to slideover the flange 3:! oi the restraining member 17 so that the spring 2315, because of the relative movement of the restraining member '17 and the arm 12?). again has cnergg v stored in it. "Plus energy is available to more the i'QSllltllllIlg member lo restraining position when the arm 2:) has been turned suilicientiy to raise its projecting portion 3;} high enough to allow inoreuicut ol' the flange till thcreiuidcr.

253 oi the arm 1 fill It will be obvious that in this modification the construction is simpler and the numberof parts less than in the switch shown in Figs. 1 and 2, but in principle the operation is substantially the same and in each'modificat-ion the Construction is such that a predetermined movement of an operating member, which may be 'actuatedin any suitable manner, is necessary to eiiect the opening of the switch so that the opening may be made synchronous with any predetermined operaion or position of a device with which the operating member is associated.

lVhile I have shown and described in detail several embodiments of my invention and described its application particularly to circuit breakers, it is obvious that it is not limited to the particular arrangements or ap plication described and I therefore aim in the appended claims to cover all such variations and modifications as fall within the spirit of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. In an electric switch of the class described, relatively movable cooperating con tacts, restraining means for holding said contacts in circuit closing position arranged to be held from restraining position While the contacts are in the circuit open position, and an operating member for actuating one of said contacts arranged upon movement in one direction to move said contacts to circuit closing position and upon a predetermined movement in the opposite direction to move said restraining means from restraining position whereby to permit movement of said contact from circuit closing position, and means for effecting the movement of the restraining means to restraining position after said contact is in circuit closing position arranged to have energy stored therein by the movement of the operating member in the circuit closing direction.

2. In an electric switch of the class described, relatively movable cooperating contacts, an operating member movable in one direction to close said contacts, a restraining member for preventing movement of said contacts to circuit opening position movable to restraining position only when said contacts are in circuit closing position and arrangedto be moved from restraining position by said operating member upon a predetermined movement thereof in the opposite direction, and a spring arranged to have energy stored therein by said operating member upon movement thereof in a direction to close said contacts whereby to bias said restraining member to restraining position.

3. In an electric switch of the class described, relatively movable cooperating contacts. an actuating member movable in one direction to close said contacts and comprising an arcuate portion, resilient means arranged to have energy stored therein upon movement of said actuating member in the direction to close. said contacts whereby to bias said actuating member for movement in the opposite direction to open said' contacts, a restraining member pivoted for movement onan axis through the center of curvature of the arcuate portion of said actuating member when the actuating member is in the contact closing position, and an operating member arranged upon movement in one direction to move said actuating member to contact closing position and to effect move ment of said restraining member over the arcuate portion of said actuating member whereby to prevent movement of said actuating member from contact closing position and upon a predetermined movement in the opposite direction to move said restraining member clear of the arcuate portion or" said actuating member whereby the actuating member is free to move from contact closing position. i i

4'. In an electric switch of the class described, relatively movable cooperating contacts, an actuating member adapted to be operated to move one of said contacts to and from circuit closing position and comprising a plurality of curved portions, a restraining member for holding said actuating member in the contact closing position movable in a path having substantially the same curvature as and concentric withone of the curved portions of said actuating member when the actuating member has been moved to the contact closing position, and an operating member arranged upon movement in one direction to engage another curved portion of said actuating member whereby to move the actuating member to the contact closing position, and to efiect movement of said restraining member in a direction to engage andhold said actuating member in the contact closing position and upon a predetermined movement in the opposite direction to move said restraining member clear of said actuating member whereby the actuating member is free to move from the contact closing position.

5. In an electric switch of the class described, relatively movable cooperating contacts, an actuating member movable in one direction to close said contacts, a spring arranged to have energy stored therein upon movement of said actuatingmember in contact closing direction whereby to bias said actuating member for movement in the opposite direction to open said contacts, a restraining member arranged to slide over a portion of said actuating member when the actuating member has been moved to contact closing position whereby to prevent movement of said actuating member in said opposite direction, an operating member arranged upon movement in one direction to engage and more said actuating member in a direetion to close said contacts and upon a predetermined movement in the opposite direction to move said restraining member clear of said portion of the actuatinr 1nen1 her. and a spring arranged to have energy stored therein upon movementof said operating member in a direction to more said actuating men'iber to contact closing position 1 whereby said restrainii'lg member is biased For movement in a direction to slide over said portion of the actuating member when the actuating member has been moved to contact closing position.

In witness whereof, I have hereunto set my hand this 19th day ofApril, 1924.

VINFIELD A. ATWOOD. 

